1. Technical Field
This device relates to elevators and more specifically to an elevator door drive.
2. Background Art
Elevators have doors that have been configured in basically the same ways for many years: each elevator car has one or more center or side opening doors to protect passengers as the car moves; and each landing has one or more hoistway doors that are configured similarly to the car doors to prevent passengers from entering the hoistway when the car is not at the landing.
Hoistway and car doors are supported similarly. The doors are suspended from their upper edges by rollers that travel longitudinally in a track attached to a lintel. The doors are guided at their bottom edges by gibs that slide in a slot in a sill.
The hoistway and car doors are opened and closed by a door operating unit or drive. The unit is disposed atop an elevator car and is attached to each car door via a complicated mechanical linkage. The linkages are complicated to allow both doors to open and close at the same speed. Each linkage is typically constructed of a plurality of gears, bars and joints.